<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <div class="box"></div>
</body>
<script>
    var box = document.querySelector(".box");

    // html元素的原型链:
    // div -> HTMLDivElement  -> HTMLElement -> Element -> Node -> EventTarget -> Object -> null


    console.log(box);
    console.dir(box);
    console.log(box instanceof HTMLDivElement);
    console.log(box instanceof Element);
</script>

</html>